The mobile wireless industry particularly the mobile telephone industry is under increasing pressure to bring products to market in shorter timeframes with increased performance and more features. This demand has forced designers to further integrate functions and reduce component part count and further concentrate on improved size reduction. One solution has been to use an internal antenna to provide cellular system, for example, GSM, WCDMA and non-cellular system, for example, Bluetooth, WLAN, BVB-H, UWB, FM-Radio communication functionality. The number of supported systems directly increases the number of required antennas, which results in a substantial increase in the component part count. Traditionally the antenna whether internal or external, has been a separate component and the parts are inserted in the mobile telephone mechanics, that is, the physical assembly of the mobile telephone. The radiating element of the separate antenna is typically connected to the mobile telephone motherboard via gold-plated pins or springs. Typically one pin is used for the feed and the other for the ground connection. Multi-band antennas typically use even more pins than a single band antenna.
A conventional known internal antenna typically comprises a metallic thin foil, radiating element that is suitably attached by gluing, welding or other appropriate attachment methods to a suitably configured plastic form. This plastic form often has multiple functions particularly in mobile telephones with an internal cellular antenna and which plastic form will also act as the acoustic cavity for the internal hands-free operation loudspeaker. In such multiple function designs, the mobile telephone motherboard is typically used as the ground plane for the antenna and the plastic form is dimensioned and shaped to maintain the antenna in a desired spaced relationship with the motherboard.
It is known to use flex-rigid technology for antennas and for baseband level electrical circuit operation applications. Typically the flex-rigid technology is used to electrically connect two printed wiring boards (PWB) together to accommodate packaging requirements or other physical packaging restraints. However it is not known to use flex-rigid technology to integrate the antenna with the wireless device motherboard. It is also known to provide a Bluetooth antenna internal to a wireless device wherein a single antenna-radiating element is carried on a flexible substrate and connected to the wireless device motherboard in a conventional well-known manner employing connectors between the flexible substrate and the motherboard. A separate flexible substrate is required to carry a corresponding different band antenna. Such flexible substrate antennas are available for example from MAXON-MOBITENNA located in Denmark. A flexible substrate antenna typical of the prior art is illustrated schematically in FIG. 1.
In foldable mobile telephones, such as for example, clam-shell type mobile telephones, the antenna radiating element may be located and carried in one half of the mobile telephone case and the RF-transceiver may be carried in the other half of the mobile telephone case wherein a coaxial cable is used to make the RF connection between the antenna radiating element and the RF transceiver located a distance apart in the two halves of the mobile telephone case.
It would be desirable therefore to integrate multiple antenna radiating elements inside the mechanics of a wireless device to provide now known and/or future developed cellular and non-cellular system communication antenna functionality with minimal if any increase in the component part count of the wireless device.
It would also be desirable to provide an RF connection between the RF transceiver and an integrated antenna radiating element carried inside the mechanics of a mobile telephone wherein the RF connection and antenna radiating element are carried on the same flexible substrate.
It is a specific goal of the present invention therefore to employ flex-rigid technology to manufacture the radiating elements of the cellular and/or non-cellular system antennas of the wireless device such as a mobile telephone in the same PWB manufacturing process as the wireless device motherboard.